Cushion clip assembly and mask assembly having same

ABSTRACT

A respiratory mask assembly includes a rigid mask frame with a rim portion including a rearwardly projecting tongue and lateral flange and a cushion having a rim with a corresponding groove and a rearwardly facing shoulder. A clip in the form of a collar passes over the cushion, engaging behind the shoulder, and has one or more securing tabs that engage recesses in the flange.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.10/751,926, filed Jan. 7, 2004, now allowed, which is a Divisional ofU.S. application Ser. No. 10/123,484, filed Apr. 17, 2002, now U.S. Pat.No. 6,796,308, which is a Continuation of U.S. application Ser. No.09/501,004, filed Feb. 9, 2000, now U.S. Pat. No. 6,412,487, which is aContinuation-in-Part (CIP) of U.S. application Ser. No. 09/498,705,filed Feb. 7, 2000, now U.S. Pat. No. 6,491,034, a CIP of U.S.application Ser. No. 09/316,227, filed May 21, 1999, now U.S. Pat. No.6,513,526; a CIP of U.S. Design Application No. 29/101,860, filed Mar.12, 1999, now U.S. Design Pat. No. D428,139; a CIP of U.S. DesignApplication No. 29/101,861, filed Mar. 12, 1999, now U.S. Design Pat.No. D430,663; a CIP of U.S. Design Application No. 29/101,862, filedMar. 12, 1999, now U.S. Design Pat. No. D428,988; and a CIP of U.S.Design Application No. 29/115,618, filed Dec. 16, 1999, now U.S. DesignPat. No. D443,355, each of which is incorporated by reference in itsentirety.

FIELD OF THE INVENTION

The invention relates to a method and apparatus for connecting a nasalor full-face mask cushion to a mask frame, where the mask is suitablefor the delivery of breathable gases to a patient for the treatment ofsleep disordered breathing (SDB).

BACKGROUND TO THE INVENTION

Nasal and full-face masks systems suitable for the delivery of air orother breathable gases to patients for the treatment of sleep disorderedbreathing may include a mask (100), a forehead support (120) andheadgear (140), as depicted in FIG. 1. The mask may comprise a rigidshell (160), termed a frame, and a soft portion (180), termed a cushion.The frame may be constructed from a material such as polycarbonate,forming a cavity which overlies the patient's nose and/or mouth. Thesoft cushion may be constructed from a material such as silicone spacingthe frame away from the patient's face to provide comfortable contact.

In the case of the Mirage® Mask (ResMed Limited), shown in FIG. 1, theheadgear (140) is constructed from fabric and includes a rear portionwhich engages the region near the occiput of the patient, and fourstraps (145) which are secured to a forehead support (2 straps) andnasal mask frame (2 straps). The straps include hook and loop material,such as Velcro™ on one side. The mask frame and forehead supportsinclude loops through which straps can pass.

In one form of known mask, the cushion and frame are glued together, asshown in FIG. 2 a to 2 c. FIG. 2 c shows a cross-section 2 c-2 c throughFIG. 2 a. The frame (160) includes a rim portion (200) surrounding therear aperture of the frame. There is a corresponding rim portion (220)on the cushion (180) which fits inside the rim (200) on the frame. Thetwo rims (200, 220) are glued together. A disadvantage with thisapproach is that the cushion cannot easily be removed for separatecleaning from the frame. Furthermore, there is an increasedmanufacturing cost since gluing requires assembly time and adhesive.

In one known mask, the Modular mask system (ResMed Limited), the frameand cushion are held, together using a tongue (300) and groove (320), asdepicted in FIG. 3 a to 3 c. The frame (160) is generally triangular infront view. In use, the front of the frame faces away from the patientand the back of the frame faces towards the patient. The rim portion(350) on the frame (160) includes an outwardly extending flange (340)and engages with a corresponding rim (360) on the cushion (180), suchthat the rims (350, 360) confront along a locus lying generally in theplane of the patient's face. The frame rim (350) further includes atongue (300) which protrudes rearwardly from the back of the frame andis received in a corresponding complementary shaped groove (320) formedin rim portion (360) of the cushion (180). In addition, the rim (350) ofthe frame (160) and the rim (360) of the cushion (180) include alignedslots (380) through which headgear straps (145) can pass. Hence theslots (380) and straps (145) make a contribution to holding the frame(160) and cushion (180) together, in addition to the use of the tongue(300) and groove (320).

In another known mask, a tongue and groove mechanism is used to hold theframe (160) and cushion (180) together, and the tongue (500), which ispositioned on the frame (160) has an irregular cross-section as depictedin FIG. 4 a to 4 c. The side (520) of the tongue (500) on the interiorof the frame (160) is flat. The other side (540) of the tongue (500) hasa lateral projection (560) approximately at right angles to the tongue(500). The groove (580) of the cushion (180) has a complimentary shape,including a lateral recess (585) for receiving projection (560). Theconnection relies on the elasticity of the cushion to retain the cushionin place.

The present invention aims to provide an improved arrangement.

SUMMARY OF THE INVENTION

The present invention provides a respiratory mask assembly fordelivering breathable gas to a patient, comprising (i) a substantiallyrigid mask frame defining a cavity with a rear opening, and a rimportion surrounding said rear opening, said rim portion including arearwardly projecting tongue, (ii) a flexible mask cushion acting tospace the mask frame away from the patient's face, said cushion having arim portion which includes a groove receiving said projecting tongue ofthe mask frame, and wherein an outer surface of the cushion forms arearwardly facing shoulder, and (iii) a clip member passing over themask cushion, having cushion retaining means engaging behind saidshoulder of the cushion and securing means which engages the mask frameso as to retain the mask cushion on the mask frame.

Preferably, the clip's securing means includes at least one securing tabwhich engages a respective recess in the mask flame, and more preferablyon a lateral flange of rim portion of the frame.

Preferably also, the clip is formed as a collar member having aplurality of tabs angularly spaced about the collar member, and the maskframe has a respective plurality of the recesses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the prior art Mirage® nasal mask system including maskframe, cushion, headgear and forehead support.

FIG. 2 a shows a perspective view of a form of prior art mask frame andcushion which are glued together

FIG. 2 b shows a side view of the mask shown in FIG. 2 a.

FIG. 2 c shows a cross-sectional view of the mask shown in FIG. 2 a.

FIG. 3 a shows a perspective view of the mask frame and cushion andstrap of the prior art ResMed Modular Mask System.

FIG. 3 b, shows a side view of the mask shown in FIG. 3 a.

FIG. 3 c shows a cross-sectional view of the mask shown in FIG. 3 a.

FIG. 4 a shows a side view of a prior art mask frame and cushionincorporating a tongue and groove mechanism with an irregularcross-section.

FIG. 4 b shows a cross-sectional detail of the mask shown in FIG. 4 awhere the cushion is secured to the frame.

FIG. 4 c shows a similar cross-sectional detail of the mask shown inFIG. 4 a where the 20 cushion is not secured to the frame.

FIG. 5 a shows a front perspective view of a nasal mask frame accordingto an embodiment of the invention.

FIG. 5 b shows a side view of the mask frame shown in FIG. 5 a.

FIG. 5 c is a front perspective view of a nasal mask frame andadjustable forehead support according to an embodiment.

FIG. 5 d is a front view of the embodiment of FIG. 5 c.

FIG. 5 e is a side view of the embodiment of FIG. 5 c.

FIG. 5 f is a rear view of the embodiment of FIG. 5 c.

FIG. 6 a shows a rear perspective view of a nasal mask cushion suitablefor the nasal mask frame of FIGS. 5 a and 5 b.

FIG. 6 b, shows a side view of the mask cushion shown in FIG. 6 e.

FIG. 6 c shows a cross-section through the mask cushion shown in FIG. 6e.

FIG. 6 d shows a bottom view of the mask cushion shown in FIG. 6 e.

FIG. 6 e shows a view from the patient (rear) side of the mask cushionshown in FIG. 6 a.

FIG. 6 f shows a top view of the mask cushion shown in FIG. 6 e.

FIG. 7 a shows a perspective view of a clip suitable for the nasal maskframe of FIGS. 5 a and 5 b and the nasal mask cushion of FIGS. 6 a to 6f.

FIG. 7 b shows a view of the clip shown in FIG. 7 a.

FIG. 7 c shows an enlarged section 7 c-7 c through the clip in theposition indicated in FIG. 7 b.

FIG. 7 d shows an enlarged section 7 d-7 d through the clip in aposition indicated in FIG. 7 b.

FIG. 7 e shows a side view of the clip shown in FIG. 7 b.

In FIGS. 6 a to 6 f and 7 a to 7 e dimensions are shown in millimeters.

FIG. 8 a is a rear perspective exploded view illustrating the cushionand frame according to a full face mask embodiment.

FIG. 8 b is an assembled view of the cushion and frame of FIG. 8 a,along with the clip.

FIG. 9 a is a front perspective exploded view illustrating the cushionand frame according to the full face mask embodiment.

FIG. 9 b is an assembled view of the cushion and frame, along with theclip.

FIG. 10 a is an exploded side view of the cushion and frame according tothe full face mask embodiment.

FIG. 10 b is an assembled view of the cushion and frame, along with theclip.

FIG. 11 a is an exploded bottom view of the frame and cushion accordingto the full face mask.

FIG. 11 b is an assembled view of the cushion and frame, along with theclip.

FIG. 12 a is an exploded top view of the frame and cushion according tothe full face mask.

FIG. 12 b is an assembled view of the cushion and frame, along with theclip.

FIG. 13 a is an exploded rear view of the frame and cushion according tothe full face mask.

FIG. 13 b is an assembled view of the cushion and frame, along with theclip.

FIG. 14 a is an exploded front view of the frame and cushion accordingto the full face mask.

FIG. 14 b is an assembled view of the cushion and frame, along with theclip.

FIG. 15 is an exploded view of an embodiment of the invention as afull-face mask.

FIG. 16 a is a schematic side view of an embodiment employing analternative clip arrangement.

FIG. 16 b is a perspective view of engagement of the clip with the maskframe.

FIGS. 16 c and 16 d are side views showing clipping of the tab into theslot on the mask frame.

DETAILED DESCRIPTION OF THE INVENTION

The method and apparatus for securing a cushion to a mask frame includesa combination of tongue and groove mechanism and a clip in the form of acollar member which passes over and engages both the cushion and theframe.

A nasal mask frame including a rim portion according to an embodiment ofthe invention is shown in FIG. 5 a and FIG. 5 b. The frame (160) isconstructed as a substantially rigid shell of polycarbonate or similartransparent plastics material, and incorporates a gas inlet aperture(610) for connection to a gas delivery conduit (not shown) of a patientgas delivery system.

The frame (160) is generally triangular in front view, covering thepatient's nose, and defines a cavity which is open at its rear, the rearopening being surrounded by a rim portion (600) which follows a locusapproximating the contours of a patient's face.

On the front surface of the frame, are strap connection points (630) forconnection of the mask to patient headgear. Connectors (200) are shownin FIGS. 5 c-5 f.

As best seen in FIG. 5 b, the rim portico (600) of the frame (160)includes a rearwardly projecting tongue (620) and a lateral flange(640). The tongue (620) has an approximately rectangular cross-section.The flange (640) is approximately perpendicular to the tongue (620) andalso has an approximately rectangular cross-section. The flange (640)includes three recesses (660) angularly spaced about the rim. Of these,only the bottom recess (660 a) and one side recess (660 b) are visiblein the view of the frame (160) shown in FIG. 5 a. The recesses are of anapproximately rectangular shape, formed in the front surface of flange(640) adjacent its edge.

FIGS. 5 c-5 f show additional views of the frame (160). As compared toFIGS. 5 a-5 b, FIGS. 5 c-5 f also show an adjustable forehead support(162) connected to the frame (160). The adjustable forehead support(162) includes a bridge portion (164) adapted to locate at least one andpreferably two spaced apart pads (not shown) adapted to contact theforehead of the patient. Projection members (166) are formed on thebridge portion (164), and can be used to secure the forehead pads to thebridge portion (164).

The forehead support (162) is coupled to the frame (160) in this exampleusing a pair of small shafts (168) formed on the forehead support (162).The frame (160) includes an extension (161) having a pair of keyedreceiving slots (163) to receive the shafts (168). Adjustment is carriedout by use of an actuator button (170) coupled in cantilever fashion tothe end of a tab (172) formed on the forehead support (162). Theactuator button (170) protrudes from the patient side of the extension(161) through a slot (174) (FIG. 5 d) formed in the extension (161),thereby exposing the actuator button (170) to the exterior surface (176)of the extension (161), which facilitates access by the patient. Theframe (160) is provided with a number of teeth (178), e.g. at leastthree, to enable the forehead support (162) to be positioned in acorresponding number of positions, so the mask can accommodate patientshaving a wide scope of facial geometries.

FIG. 5 f shows that the tongue (620) and the flange (640) have agenerally triangular shape. An apex (181) of the tongue (620) isprovided adjacent to a point where the extension (161) extends upwardlyabove the main part of the frame (160). A receiving space (182) isdefined in a region of the extension (161) just above the apex (181) ofthe tongue (620). Sidewalls (184) define the side boundaries of thereceiving space (182), while the end (186) of the tab (172) defines theupper boundary of the receiving space (182). The purpose of thereceiving space (182) will be described below in conjunction with FIGS.7 a-7 e.

The thickened rim portion (700) of the cushion has an inwards step (720)in its outer surface, forming a rearwardly facing shoulder.

The cushion is formed of soft material such as silicone, and projectsrearwardly of the mask frame so as to space the rigid frame away fromthe patient's face. The width (W) of the cushion is about 71.2 mm, asshown in FIG. 6 d. The width (W) of the aperture 210 is about 31.7 mm.The height (H) is about 72.1 mm. The height of the aperture 210 is about36.7 mm. The thickness (t) of the lower sidewall is about 6.6 mm, asshown in FIG. 6 c.

A clip (800) according to an embodiment of the invention, suitable for anasal mask, is shown in FIG. 7 a to 7 e. The clip is formed as a collarof a complementary shape to the rims of the mask cushion (700) and frame(600) and fits over them. The clip is constructed from polycarbonate orsimilar material. In the illustrated embodiment the clip (800) includesthree securing tabs (820) such that inwards projections on the detentsare formed as resilient detents which extend past the outer edge offlange (640) to be retained in recesses (660) on the front of the flange(640). To disengage, for example for cleaning of the mask assembly orreplacement of the cushion, the detents may be forced outwardly againsttheir natural resilience to release from the recesses (660) and rideover the outer edge of flange (640). In other embodiments, other numbersof securing tabs may be used.

The rear of the clip has an inwards flange (840) which engages behindthe shoulder (720) of the cushion so as to hold the cushion securely inposition on the frame when the tabs (820) are engaged on the rim (600)of the frame.

Furthermore, the clip (800) includes a guide projection (802) located atan apex (804) of the clip (800), as shown in FIGS. 7 a, 7 b and 7 e. Theprojection (802) is positioned diametrically across from the lowermostsecuring tab (820), as best seen in FIG. 7 b. The projection (802) hasan arcuate shape that generally matches the curve of the clip (800) atthe apex (804) thereof.

As shown in FIG. 7 b. the length (L) of each of the securing tabs isabout 18.0 mm. The width (w) of the guide projection (802) is about 15.5mm, and the width (W) of the base of the clip (800) is about 73.83±0.5mm.

The guide projection (802) helps guide the clip (800) into place whenthe clip (800) is secured to the frame (160). In this context, the guideprojection (802) is not shown as including inwardly facing detents,which distinguish the guide projection (802) from the securing tabs(820), which have inwardly facing detents. In particular, the guideprojection (802) is intended to be received within the receiving space(182), which is shown in FIG. 5 f. The guide projection (802) has ashape that is complementary to the shape of the apex (181) of the tongue(620) of the frame (160). The width (w) of the guide projection (802) isdimensioned such that it fits between sidewalls (184) of the extension(161).

The invention is also suitable for a full-face mask system. FIGS. 8 a-15show several exploded views of a Mirage® full-face mask which includesan embodiment of the invention, including a mask frame (160), cushion(180) and clip (800). While FIGS. 8 a, 9 a, 10 a, 11 a, 12 a, 13 a and14 a show an exploded view of the frame (160) and the cushion (180),FIG. 15 shows an exploded view including the clip (800) as well. FIGS. 8b, 9 b, 10 b, 11 b, 12 b, 13 b and 14 b show the assembled view of thecushion, clip and frame, with the cushion and frame shown in phantom andthe clip shown in solid lines. The clip (800) in FIG. 8 b can be seen tooverlie the cushion (180) since a sidewall (801) of the clip (800)instead of the sidewall (181) of the cushion (180) is visible. Inaddition, at least one of the securing tabs (820) can be seen. In FIGS.9 a-12 a and 14 a, recesses (660) can be seen on the frame (160), andFIGS. 9 b-12 b and 14 b show the securing tabs (820) which engage withthe recesses (660). FIG. 14 b in particular shows that the clip (800)completely surrounds the frame (160), and each of the securing tabs(820) is positioned within respective recesses (660). FIG. 14 b alsoshows that the recesses (660) are slightly larger than the securing tabs(820) in length so as to allow for a small degree of misalignment, tofacilitate assembly. The frame is adapted to cover both the mouth andnose region of the patient's face, and includes a gas inlet aperture(910), connection points (920) for headgear straps, an aperture (930)for receiving an air vent (940) (FIG. 15) and ports (950).

The interengagement of the clip (800) and the respective rim portions(600), (700) of the frame (100) and cushion (180) are similar inprinciple and construction to those described above with reference toFIGS. 5 a to 5 f and 7 a to 7 e, except there are six angularly spacedtabs (820) and the respective recesses (660). As in the nasal maskassembly, the rim portion (600) of the frame includes a tongue (620) anda lateral flange (650) with recesses in its front surface adjacent itsedge, the rim portion (700) of the cushion having a complementary groove(740) and rear shoulder surface (720), and the clip having a flange(840) and securing tabs (820) generally as described above for the nasalmask assembly.

FIGS. 16 a to 16 d illustrate an alternative clipping arrangement. Theclip (1000) is again formed generally as a collar, with a rear flange(1020) for engaging the shoulder of the cushion as previously described.

At the base of the clip is a securing hook (1040) which hooks over andengages behind the lateral flange of the mask frame (160), allowing theclip to pivot.

At the top of the clip is a resilient detent arrangement (1060), adaptedfor engagement with an inverted T-shaped slot (1080) on the upperextension of the mask frame (160) as best shown in FIGS. 9 a to 9 c.

As shown, the detent is formed as a resilient U-shape with rearwardlyfacing shoulders (1050) on either side of a narrow tab (1070). In use,the clip is pivoted to force the U-shaped detent through the wide partof the T-slot (1080), until the shoulders (1050) clear the rear surfaceof the slot. The resilience of the detent then forces tab (1070) intothe leg (1030) of the T-slot, to retain the clip in position. Todisengage the clip, the tab (1070) is depressed to allow the detent topass back through the slot

In an unillustrated embodiment of the invention, the tongue and grooveof the frame and cushion have an irregular cross-section, for example asshown in FIG. 4 a to 4 c.

Although the invention has been described with reference to particularembodiments, it is to be understood that these embodiments are merelyillustrative of the application of the principles of the invention.Numerous modifications may be made in the illustrative embodiments ofthe invention and other arrangements may be devised without departingfrom the spirit and scope of the invention.

1-9. (canceled)
 10. A clip assembly for retaining a mask cushion to amask frame, the clip assembly including a main body having a resilientdetent movable between a first position in which the detent isrelatively uncompressed and a second position in which the detent isrelatively compressed, whereby in the second position the detent isconfigured to be guided through a slot located on the frame, and, uponinsertion, the detent is releasable so that the detent assumes the firstposition in which the detent is lockable relative to the slot of theframe.
 11. A clip assembly as claimed in claim 10, wherein the main bodyhas a generally triangular shape.
 12. A clip assembly as claimed inclaim 10, wherein the main body includes a hook adapted to be releasablyengaged with a flange provided to the frame and allowing the clipassembly to pivot relative to the frame, the detent being adapted forengagement with the slot upon pivoting of the hook with respect to theframe.
 13. A clip as claimed in claim 10, wherein the hook and detentare formed as an integral one-piece unit.
 14. A clip as claimed in claim10, wherein the detent further includes at least one shoulder to engagewith a first portion of the slot, and a tab to engage with a secondportion of the slot.
 15. A clip as claimed in claim 14, wherein thedetent is configured for movement to the second position by displacementof the tab to unlock the detent from the slot.
 16. A clip as claimed inclaim 14, wherein the at least one shoulder includes two shoulders andthe tab is provided between the two shoulders at a distal end of thedetent.
 17. A clip as claimed in claim 10, wherein the detent issubstantially U-shaped.
 18. A mask assembly comprising: a mask framehaving a slot; a mask cushion provided to the frame; and a clip assemblyfor retaining the mask cushion to the mask frame, the clip assemblyincluding a main body having a resilient detent movable between a firstposition in which the detent is relatively uncompressed and a secondposition in which the detent is relatively compressed, whereby in thesecond position the detent is configured to be guided through the slot,and, upon insertion, the detent is released such that the detent assumesthe first position in which the detent is locked relative to the slot.19. A mask assembly as claimed in claim 18, wherein the main body has ahook adapted to be releasably engaged with the base side of the framethat allows the clip to pivot relative to the base side.
 20. A maskassembly as claimed in claim 18, wherein the hook is open ended.
 21. Amask assembly as claimed in claim 19, wherein the hook and detent areformed as an integral one-piece unit.
 22. A mask assembly as claimed inclaim 18, wherein the clip assembly is selectively engageable with themask cushion.
 23. A mask assembly as claimed in claim 18, wherein theslot is T-shaped and the detent includes two shoulder portions and a tabtherebetween, the tab engaging with a leg of the T-shaped slot uponassembly of the clip assembly and the frame with the cushiontherebetween.
 24. A mask assembly as claimed in claim 23, wherein thetab extends from one side of the frame to another side of the frame whenassembled.
 25. A mask assembly as claimed in claim 18, wherein the mainbody is made of polycarbonate.
 26. A clip assembly for retaining a maskcushion to a generally triangular mask frame having a base side, theclip assembly including a generally triangular shaped main body defininga base portion corresponding to a base portion of the frame and two sideportions forming an apex, the main body including a hook provided to thebase of the main body and adapted to be releasably engaged with the baseside of the frame and allowing the clip to pivot relative to the base,the clip assembly further including a resilient detent having a distalend with a tab, a proximal end and a shoulder oriented to face generallytowards the cushion and outward of the main body, the tab beingconfigured to protrude through a slot located in the frame upon pivotingof the hook with respect to the frame so as to locate the shoulderagainst the frame.
 27. A clip assembly as claimed in claim 26, whereinthe hook is an open-ended hook.
 28. A clip assembly as claimed in claim26, wherein the main body is made of polycarbonate.
 29. A clip assemblyas claimed in claim 26, wherein the slot is T-shaped.